2) This is more technical question. I want to know if Scan tools that support these standards can provide real-time data,
vehicle speed, for example.

The problem is that scan tool not connected directly to speed sensor.
So, the question is if vehicle ECU itlself can provide real-time data,
here I mean deterministic latency and/or if exists timestamps for this data.

Also, the question is if scan tool also can provide this data in real-time.

And if such latency is specifyed in standards J1708/J1587 and J1939 ?

3) If exists for standards J1708/J1587 and J1939 some chipset like as ELM for OBD-II interface ?